Nuclear fusion is always “50 years away.” But now it could finally, almost be here.

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In the suburbs of Vancouver, a team is working on what they think is humanity's best chance at clean, unlimited power, something we desperately need. A startup called General Fusion is building a nuclear fusion reactor and, if they succeed, it could mean the end of the fossil fuel era. Instead, we'd get our power from the same process that occurs in stars—at least, that's the dream.

Because of climate change, nuclear power—which produces no greenhouse gases—is looking more attractive. But the big problem is what to do with the radioactive waste left behind. Nuclear fusion promises to solve the problems of traditional fission power. Its fuel is abundant (seawater!), and it has a harmless helium byproduct. But until recently, the challenges of fusion seemed insurmountable. Now, big name investors like Jeff Bezos are lending a hand to General Fusion, which is attempting a whole new approach.

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Unlike the nuclear fission that powers conventional reactors today, in which atoms are split apart, fusion power is generated when you smoosh two smaller atoms into a larger one inside a containment device. The math behind fusion says this reaction has to result in the loss of a bit of mass and, well, due to that little equation E=mc2, that mass turns into a lot of energy. Like, a ton.

Here's the rub: so far, all fusion solutions still require more power to run than they create. Overhead costs mean current experimental applications just aren't energy efficient enough to produce net power. So, fusion technology has a perpetual reputation for being decades away.

"We can definitely make fusion," George Rubin, VP of business development for General Fusion, told Motherboard over the phone. "We have not been able to demonstrate fusion that produces more energy than we have to put into it. But it's not like we're violating the laws of the universe here."

"The scientific achievements of large fusion projects have created the knowledge base that can now fuel this development," said Rubin. "You also have a lot of developments in parallel industries," like materials, he continued. "High temperature superconductors, lasers, and pulse power systems were not developed for fusion per se, but they all have a dramatic impact on what you can do."

General Fusion's plan is to work around the really complicated problems that need superconductors and propose an alternative reactor design called Magnetized Target Fusion (MTF).

Instead of relying on huge lasers, MTF will attempt to create fusion by injecting a stream of deuterium-tritium plasma into a 3m sphere. The walls of the sphere are lined with lead-lithium liquid metal, which is being pumped to create a vortex (like water draining from a tub). The plasma, mixing with the liquid metal vortex, is then compressed once every second by acoustic waves from 200 pistons that will encircle the reactor. This compression heats everything up to 150 million degrees celsius so fusion occurs. General Fusion calls it the spheromak.

MTF also solves a problem that experimental fusion reactor designs still contend with. The liquid metal liner can be linked to a heat exchanger, which means it can generate steam to spin a turbine. Other types of reactor still need to figure out how to harvest the heat created.

But there's one giant hurdle the Vancouver company has yet to face: heating up the plasma to 150 million degrees. Unstable plasma been a major stumbling point for other approaches, and General Fusion will only discover what happens when they start up their first prototype, in what they hope will be three-to-five years.

In many ways, the MTF concept anticipates problems that other reactors have faced. For example, the liquid metal liner solves the first wall problem because it stops neutrons from degrading the spheromak's steel enclosure. General fusion thinks the plasma stability problem is accounted for because the actual reaction time is so short.

"We only need the plasma to last on the order of hundreds of microseconds," said General Fusion spokesperson Tim Howard. "We anticipate that with the substantial plasma physics expertise we've developed over recent years that this will be a manageable challenge."

The reactor will need tiny amounts of plasma injected every second, which is then compressed to reach millions of degrees. Image: General Fusion

With an aim to create a healthy fusion industry here by 2030, General Fusion sees a need to attract more expertise to Canada through funding of academic ventures and private business in the emerging market. The federal government is finally coming around to funding future tech through initiatives like the machine learning Vector Institute in Toronto. The early days of fusion offer opportunities to get ahead of the competition, General Fusion's supporters argue.

The 2030 timeline is a big deal. While renewable sources of energy are going to play a huge role in the future power grid, they don't offer the same capacity as something like nuclear, gas, or coal. And with rising costs of gas and coal due to upcoming carbon fees, finding a way to make nuclear work will become a more affordable option.

Fusion power could be what humanity needs to break itself from its carbon habit, but it needs support today to become the power source of the future.

Correction: An earlier version of this piece said that the timeline for General Fusion's prototype isn't clear. In fact, they are aiming for three-to-five years, so the piece has been updated with this information. In addition, the goal is to grow academic and private efforts by 2030, not to have a full reactor, as the piece initially said. Motherboard regrets the errors.